Q: Sankara says we are all free, not bound, and that we shall all go back to God from whom we have come as sparks from a fire. Then why should we not commit all sorts of sins?
A: It is true we are not bound and that the real Self has no bondage. It is true that you will eventually go back to your source. But meanwhile, if you commit sins, as you call them, you will have to face the consequences of such sins. You cannot escape them. If a man beats you, then, can you say, `I am free, I am not bound by these beatings and I don't feel any pain. Let him beat on'? If you can feel like that, you can go on doing what you like. What is the use of merely saying with your lips 'I am free'?
Q: It is said that the whole universe is God's play of consciousness and that everything is full of Brahman. Then why should we say that bad habits and bad practices should be discarded?
A: Suppose there is some wound inside the human body. If you neglect it, on the assumption that it is only a small part of the body, it causes pain to the whole body. If it is not cured by ordinary treatment, the doctor must come, cut off the affected portion with a knife and remove the impurities. If the diseased part is not cut off it will fester. If you do not bandage it after operating, pus will form. It is the same thing with regard to conduct. Bad habits and bad conduct are like a wound in the body. Every disease must be given appropriate treatment.
Source: Be as you are – The teachings of Sri Ramana Maharishi By David Godman
My Friend Subramanian.R wants to add few more information
Yes. Bad habits and bad conducts are like wound. But sometimes even good acts can create sins very indirectly. Bhagavan Ramana has also said about this in some conversation.
Once there was a Siva bhakta chanting Namasivaya always. One day, during his puja, some beggar came and asked for some money. Since the meal was not ready, he came out and gave him a measure of rice, for he had no money either to give.
This beggar went and sold the rice and bought a fishing gadget. With that he caught fish in large numbers. Then he with the additional earnings, brought a net also. More money came since he had huge haul of fish every day. Then he bought a boat and thus started catching tons of fish every day. He became an exporter of fish in cold storage containers and became a millioner.After some years he died. The Siva bhakta also died. Siva bhakti surprisingly was taken to hell. He wondered and ask Yama what sins he had committed. Yama asked Chitragupta to bring the accounts book of merits and demerits. There it was written that he had killed one billion fish! Then Yama explained: You gave a measure of rice to the beggar. The beggar did all these. But your rice is the capital for the whole trade. So you get capital punishment! This bhakta then finished his period in hell and came back and pursued his Siva
puja. In this birth, he used to give only cooked rice and made the beggars to eat it then and there and then leave his house!
When Ravana's hands were caught under Kailas when he tried to lift it, and when Siva stamped his toe on him. He cried for 1000 years.No retribution. Then there came the Sage Vageesa and he said: Even if you weep for 10000 years, you will have no relief. Best thing is you sing Sama Veda and Siva will be pleased. Ravana cut one of his ten heads and sang the Sama Veda and Siva was pleased. Siva then gave him half a million years of lifetime! But Ravana misused this longeivity of life and started doing all sorts of atrocities, the major thing being taking away the women from their households.
The householders beat their stomach and cried. Their stomach was burning with anger and misery. This Sage Vageesa, because of his indirect help, did not get Siva padam. He was born again as Saint Tirunavukkarasar and cried due to colic pain for long years, [when he was a Jain follower] before he came back to Saivism and with the vibhuti given by his sister Tilakavadi, his colic pain was cured! He started singing Siva nama and he became Saint Tirunavukkarasar.He composed Tevaram book 4,5 and 6.
Saint Avvaiyar has therefore said: Please give alms after knowing the vessel [that is the nature of the recipient.].